This disclosure relates to a gas turbine engine with an adjustable vane. More particularly, the disclosure relates to an adjustable vane sealing arrangement.
A gas turbine engine uses a compressor section that compresses air. The compressed air is provided to a combustor section where the compressed air and fuel is mixed and burned. The hot combustion gases pass through a turbine section to provide work that may be used for thrust or driving another system component.
In general, it is often the case that the temperature of the gases passing through the flow path of a turbine stage may exceed a maximum allowable temperature of the turbine vane material, and therefore it is necessary to provide a continuous supply of cooling air to the interior of the airfoil in order to limit its maximum temperature. A turbine section typically has one or more fixed stages and one or more rotatable stages. A typical cooling scheme is to feed the cooling air though openings in fixed stator vanes. Such openings are situated directly over the attached airfoil, such that the cooling air enters directly into passages internal to the airfoil. Inner and outer diameter platforms serve to constrain the stator vane relative to the static structure of the turbine section, and additionally serve to define the inner and outer diameter flow path boundaries.
In certain designs, variable stator vanes may be used in the fixed stage where the airfoil portion of the vanes is rotatable about a radial axis. In one embodiment, such turbine vanes include an airfoil and a cylindrical trunnion that connects the airfoil to a support structure, such as inner and outer cases, via a set of bushings or bearings. Cooling air may be provided to the airfoil through an aperture in the trunion. There is typically a gap between the moveable airfoil section and the support structure that permits the airfoil section to rotate freely without interference or binding with the support structure. One or more actuators selectively rotates the airfoil section of the variable vanes about the trunions between desired positions.